.preview{
    width: 60%;
    height: 300px;
}

.hider1{
    width: 271px;
    height: 300px;
    background-color: white;
    position: absolute;
    left: 0px;  
}

.hider2{
    width: 300px;
    height: 300px;
    background-color: white;
    position: absolute;
    left: 542px;
}

img{
    left: 300px;
    width: 80%;
    height: 300px;
}